The Transgenic and Knockout Mouse Shared Resource was established in 1996 at the School of Medicine. The overall objective of this Shared Resource is to provide genetically modified mouse models and supporting technologies to Stanford Cancer Center investigators at cost-effective rates. This Shared Resource provides the necessary scientific and technical foundation and physical plant to conduct transgenic, gene targeting and embryonic stem cell research. The Shared Resource serves an important role in advancing cancer research by providing a wide spectrum of mouse embryo and stem cell manipulation and microinjection services to investigators as a highly specialized technology. The objectives of the Shared Resource are to: Consult in all aspects of creating and characterizing genetically modified mice Produce transgenic and knockout mice by microinjection Manipulate mouse embryonic stem cells for gene targeting Provide molecular and biological reagents associated with production of genetically modified mice Substantial cost savings, efficiencies and scientific advances accrue from providing these services through a centralized facility. The Shared Resource has generated over 500 mouse models in the last 5 years, each with multiple independent lines. The Shared Resource's services were acknowledged in more than 50 publications in peer-reviewed journals. In fiscal year 2005, there were 192 service requests, with Cancer Center members accounting for 56% of overall use. Cancer Center members representing eight out of ten Programs utilized the Shared Resource. Future plans for the Shared Resource include implementation of somatic cell nuclear transfer and tetraploid blastocyst complementation services, and derivation of new ES cell lines.